Summary

This amendment supersedes Airworthiness Directive (AD) 88-05- 05, which currently requires the following on certain The New Piper Aircraft, Inc. (Piper) PA31, PA31P, and PA31T series airplanes: repetitively inspecting both the left and right main landing gear (MLG) forward sidebrace, and replacing any cracked MLG forward sidebrace. The Federal Aviation Administration's policy on aging commuter-class aircraft is to eliminate or, in certain instances, reduce the number of certain repetitive short-interval inspections when improved parts or modifications are available. This action retains the current repetitive inspection and necessary replacement requirements contained in AD 88- 05-05, and requires incorporating both a left and right MLG forward sidebrace of improved design as terminating action for the repetitive inspection requirement. The actions specified in this AD are intended to prevent the MLG from retracting because of a cracked MLG forward side brace, which, if not detected and corrected, could result in gear collapse and loss of control of the airplane during landing operations.

Full text

SUMMARY: This amendment supersedes Airworthiness Directive (AD) 88-05-
05, which currently requires the following on certain The New Piper
Aircraft, Inc. (Piper) PA31, PA31P, and PA31T series airplanes:
repetitively inspecting both the left and right main landing gear (MLG) forward sidebrace, and
replacing any cracked MLG forward sidebrace. The Federal Aviation
Administration's policy on aging commuter-class aircraft is to
eliminate or, in certain instances, reduce the number of certain
repetitive short-interval inspections when improved parts or
modifications are available. This action retains the current repetitive
inspection and necessary replacement requirements contained in AD 88-
05-05, and requires incorporating both a left and right MLG forward
sidebrace of improved design as terminating action for the repetitive
inspection requirement. The actions specified in this AD are intended
to prevent the MLG from retracting because of a cracked MLG forward
side brace, which, if not detected and corrected, could result in gear
collapse and loss of control of the airplane during landing operations.
DATES: Effective June 27, 1996.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of June 27, 1996.
ADDRESSES: Service information that applies to this AD may be obtained
from The New Piper Aircraft, Inc., Customer Services, 2926 Piper Drive,
Vero Beach, Florida 32960. This information may also be examined at the
Federal Aviation Administration (FAA), Central Region, Office of the
Assistant Chief Counsel, Attention: Rules Docket 90-CE-62-AD, Room
1558, 601 E. 12th Street, Kansas City, Missouri 64106; or at the Office
of the Federal Register, 800 North Capitol Street NW., suite 700,
Washington, DC.
FOR FURTHER INFORMATION CONTACT: Christina Marsh, Aerospace Engineer,
FAA, Atlanta Aircraft Certification Office, Campus Building, 1701
Columbia Avenue, suite 2-160, College Park, Georgia 30337-2748;
telephone (404) 305-7362; facsimile (404) 305-7348.
SUPPLEMENTARY INFORMATION:
Events Leading to the AD
A proposal to amend part 39 of the Federal Aviation Regulations (14
CFR part 39) to include an AD that would apply to Piper PA31, PA31P,
and PA31T series airplanes was published in the Federal Register on
December 7, 1995 (60 FR 62776). The action proposed to supersede AD 88-
05-05 with a new AD that would (1) retain the requirement of
repetitively inspecting both the left and right MLG forward sidebrace
for cracks, and replacing any cracked MLG forward sidebrace; and (2)
require replacing both the left and right MLG forward sidebrace with a
part of improved design, part number (P/N) 85165-02 (left) and 85165-03
(right) or P/N 85166-02 (left) and 85166-03 (right), as applicable, as
terminating action for the repetitive inspection requirement.
Accomplishment of the proposed inspections would be in accordance with
Piper Service Bulletin No. 845A, dated October 9, 1987. The improved
MLG forward sidebrace installations would be accomplished in accordance
with the applicable maintenance manual.
Interested persons have been afforded an opportunity to participate
in the making of this amendment. No comments were received on the
proposed rule or the FAA's determination of the cost to the public.
After careful review of all available information related to the
subject presented above, the FAA has determined that air safety and the
public interest require the adoption of the rule as proposed except for
minor editorial corrections. The FAA has determined that these minor
corrections will not change the meaning of the AD and will not add any
additional burden upon the public than was already proposed.
Cost Impact
The FAA estimates that 2,384 airplanes in the U.S. registry will be
affected by this AD, that it will take approximately 8 workhours per
airplane to accomplish the required replacement, and that the average
labor rate is approximately $60 an hour. Parts cost approximately
$1,000 per airplane (2 MLG forward sidebraces per airplane at
approximately $500 per sidebrace). Based on these figures, the total
cost impact of this AD on U.S. operators is estimated to be $3,528,320
or $1,480 per airplane. This figure is based on the assumption that no
affected airplane owner/operator has accomplished the required
replacement.
Piper has informed the FAA that parts have been distributed to
owners/operators to equip 2,123 of the affected airplanes (4,246 MLG
forward sidebraces of improved design). Assuming that each set of parts
has been installed on an affected airplane, the cost impact of the
required replacement upon U.S. owners/operators of the affected
airplanes is reduced by $3,142,040 from $3,528,320 to $386,280.
The FAA's Aging Commuter Class Aircraft Policy
This AD is part of the FAA's aging commuter class airplane policy,
which briefly states that, when a modification exists that could
eliminate or reduce the number of required critical inspections, the
modification should be incorporated.
The intent of the FAA's aging commuter airplane program is to
ensure safe operation of commuter-class airplanes that are in
commercial service without adversely impacting private operators. The
FAA believes that a large number of the remaining 261 affected
airplanes (2,384 affected airplanes - 2,123 airplanes with a set of
parts distributed) that will be affected by this AD are operated in
various types of air transportation. This includes scheduled passenger
service, air cargo, and air taxi.
This AD allows 1,200 hours time-in-service (TIS) after the
effective date of the AD before mandatory accomplishment of the design
modification. The average utilization of the fleet for those airplanes
in air transportation is between 25 to 40 hours TIS per week. Based on
these figures, operators of commuter-class airplanes involved in
commercial operation will have to accomplish the required replacement
within 7 to 12 months after the AD becomes effective. For private
owners, who typically operate between 100 to 200 hours TIS per year,
this allows 6 to 12 years before the required replacement will be
mandatory.
The FAA established the 1,200 hours TIS replacement compliance time
based on its engineering evaluation of the problem. Among the issues
examined during this engineering evaluation were analysis of service
difficulty reports, the difficulty level of the inspection, and how
critical the situation would be if cracks occurred in the subject area
despite accomplishment of the repetitive inspections.
Usually, the FAA establishes the mandatory design modification
compliance time on AD's affecting aging commuter-class airplanes upon
the accumulation of a certain number of hours TIS on the airplane. For
this action, the FAA is mandating the replacement for all operators
``within the next 1,200 hours TIS after the effective date of this
AD.'' The total TIS levels of the airplane fleet vary from under 1,000
hours TIS to over 5,000 hours TIS, and annual accumulation rates vary
from 50 hours TIS to over 1,000 hours TIS. Establishing a long-term set
compliance time of hours TIS accumulated on Piper PA31, PA31P, and
PA31T series airplanes (such as 5,000 hours TIS) imposes an undue
burden on the manufacturer of having to maintain a supply of
replacement parts for the entire fleet when many airplanes in the fleet
may never reach this compliance time. Instead, the FAA believes that Piper should maintain parts for
several years; in this case about 12 years to allow low-usage airplanes
time to accumulate the 1,200 hours TIS after the effective date of the
AD. The FAA has determined that the compliance time of this AD provides
the level of safety required for commuter air service while still
minimizing the impact on the private airplane owners of Piper PA31,
PA31P, and PA31T series airplanes.
Regulatory Impact
The regulations adopted herein will not have substantial direct
effects on the States, on the relationship between the national
government and the States, or on the distribution of power and
responsibilities among the various levels of government. Therefore, in
accordance with Executive Order 12612, it is determined that this final
rule does not have sufficient federalism implications to warrant the
preparation of a Federalism Assessment.
For the reasons discussed above, I certify that this action (1) is
not a ``significant regulatory action'' under Executive Order 12866;
(2) is not a ``significant rule'' under DOT Regulatory Policies and
Procedures (44 FR 11034, February 26, 1979); and (3) will not have a
significant economic impact, positive or negative, on a substantial
number of small entities under the criteria of the Regulatory
Flexibility Act. A copy of the final evaluation prepared for this
action is contained in the Rules Docket. A copy of it may be obtained
by contacting the Rules Docket at the location provided under the
caption ADDRESSES.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.
Adoption of the Amendment
Accordingly, pursuant to the authority delegated to me by the
Administrator, the Federal Aviation Administration amends part 39 of
the Federal Aviation Regulations (14 CFR part 39) as follows:
PART 39--AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C 106(g), 40113, 44701.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by removing Airworthiness Directive
(AD) 88-05-05, Amendment 39-5861, and by adding a new AD to read as
follows:
96-10-14 The New Piper Aircraft, Inc. (formerly Piper Aircraft
Corporation): Amendment 39-9621; Docket No. 90-CE-62-AD. Supersedes
AD 88-05-05, Amendment 39-5861.
Applicability: The following model and serial number airplanes,
certificated in any category, that do not have left and right main
landing gear (MLG) forward sidebraces of improved design installed,
part numbers (P/N) 85165-02 (left) and 85165-03 (right) or P/N
85166-02 (left) and 85166-03 (right).
------------------------------------------------------------------------
Models Serial Nos.
------------------------------------------------------------------------
PA31, PA31-300, and PA31-325........ 31-2 through 31-8312019.
PA31-350............................ 31-5001 through 31-8553002.
PA31P............................... 31P-2 through 31P-7730012.
PA31P-350........................... 31P-8414001 through 31P-8414050.
PA31T............................... 31T-7400002 through 31T-8120104.
PA31T1.............................. 31T-7804001 through 31T-8304003
and 31T-1104004 through 31T-
1104017.
PA31T2.............................. 31T-8166001 through 31T-8166076
and 31T-1166001 through 31T-
1166008.
------------------------------------------------------------------------
Note 1: This AD applies to each airplane identified in the
preceding applicability provision, regardless of whether it has been
modified, altered, or repaired in the area subject to the
requirements of this AD. For airplanes that have been modified,
altered, or repaired so that the performance of the requirements of
this AD is affected, the owner/operator must request approval for an
alternative method of compliance in accordance with paragraph (g) of
this AD. The request should include an assessment of the effect of
the modification, alteration, or repair on the unsafe condition
addressed by this AD; and, if the unsafe condition has not been
eliminated, the request should include specific proposed actions to
address it.
Compliance: Required as indicated in the body of this AD, unless
already accomplished.
To prevent the MLG from retracting because of a cracked MLG
forward side brace, which, if not detected and corrected, could
result in gear collapse and loss of control of the airplane during
landing operations, accomplish the following:
(a) Within the next 100 hours time-in-service (TIS) after the
effective date of this AD, unless already accomplished (compliance
with AD 88-05-05), and thereafter at intervals not to exceed 100
hours TIS until the modification required by paragraph (d) of this
AD is incorporated, inspect (using dye penetrant methods) both the
left and right MLG sidebraces for cracks. Accomplish the inspections
in accordance with the INSTRUCTIONS section of Piper Service
Bulletin No. 845A, dated October 9, 1987.
(b) The initial dye penetrant inspection type must be utilized
for all future repetitive inspections. Dye penetrant inspection
types consist of Type I: fluorescent; Type II: non-fluorescent or
visible dye; and Type III: dual sensitivity.
(c) If cracks are found during any of the inspections required
in paragraph (a) of this AD, prior to further flight, replace the
cracked MLG sidebrace with a part of improved design, P/N 85165-02
(left) or 85165-03 (right) or P/N 85166-02 (left) or 85166-03
(right), as applicable. Accomplish this replacement in accordance
with the applicable maintenance manual.
(d) Within the next 1,200 hours TIS after the effective date of
this AD, unless already accomplished as required by paragraph (c) of
this AD, replace both the left and right MLG side braces with parts
of improved design, P/N 85165-02 (left) and 85165-03 (right) or
P/N 85166-02 (left) and 85166-03 (right), as applicable. Accomplish
these replacements in accordance with the applicable maintenance
manual.
(e) Installing both the left and right MLG side braces with
parts of improved design, P/N 85165-02 (left) and 85165-03 (right)
or P/N 85166-02 (left) and 85166-03 (right), as applicable, as
required by paragraph (d) of this AD is considered terminating
action for the repetitive inspection requirement of this AD.
(f) Special flight permits may be issued in accordance with
sections 21.197 and 21.199 of the Federal Aviation Regulations (14
CFR 21.197 and 21.199) to operate the airplane to a location where
the requirements of this AD can be accomplished.
(g) An alternative method of compliance or adjustment of the
initial or repetitive compliance times that provides an equivalent
level of safety may be approved by the Manager, Atlanta Aircraft
Certification Office (ACO), Campus Building, 1701 Columbia Avenue,
suite 2-160, College Park, Georgia 30337-2748. The request shall be
forwarded through an appropriate FAA Maintenance Inspector, who may
add comments and then send it to the Manager, Atlanta ACO.
Note 2: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Atlanta ACO.
Note 3: Alternative methods of compliance approved in accordance
with AD 88-05-05 (superseded by this AD) are not considered approved
for this AD.
(h) The inspection required by this AD shall be done in
accordance with Piper Service Bulletin No. 845A, dated October 9,
1987. This incorporation by reference was approved by the Director
of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR
part 51. Copies may be obtained from The New Piper Aircraft, Inc.,
2926 Piper Drive, Vero Beach, Florida 32960. Copies may be inspected
at the FAA, Central Region, Office of the Assistant Chief Counsel,
Room 1558, 601 E. 12th Street, Kansas City, Missouri, or at the
Office of the Federal Register, 800 North Capitol Street NW., suite
700, Washington, DC.
(i) This amendment (39-9621) supersedes AD 88-05-05, Amendment
39-5861.
(j) This amendment (39-9621) becomes effective on June 27, 1996. Issued in Kansas City, Missouri, on May 8, 1996.
Henry A. Armstrong,
Acting Manager, Small Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 96-12390 Filed 5-16-96; 8:45 am]
BILLING CODE 4910-13-U